1. Field of the Invention
This invention is concerned with method and apparatus for preventing unwanted operation of a sensor activated flush valve.
More particularly, the invention is concerned with preventing operation of the sensor activated flush valve when there is a power loss or outage. The invention is also concerned with preventing activation of sensor activated flush valves when power is restored after a power loss or outage.
2. Description of the Prior Art
Heretofore, when a sensor activated flush valve loses power or there is a power outage, the circuitry for the flush valve is rendered operative and all the flush valves in an installation commence operation when power is restored, but since there is insufficient flush water supply to terminate the flushing operation, such flush valves then continue to operate after the power is restored. Other prior art of which applicant is aware are U.S. Pat. Nos. 3,908,204 and 4,309,781.
Heretofore, infrared sensing systems have been used in connection with mechanisms to operate flush valves. Such systems use a single filter through which both the infrared radiation energy is transmitted and reflected both back to a control module.
Also, because of lack of adjustability in connection with some prior art sensing systems, it is not possible to adjust the sensitivity of the receiver as well as the direction of the beam so that the beam may see an unwanted object or false object.
When one lens sees the other, that is, when the lens which receives the reflected light sees the lens transmitting the energy, this creates heat build-up, and the sensor in certain instances will keep the flush valve in a constant working mode and the circuitry therefor can burn itself out. Also, where only one lens is used for transmission and reception, overheating results.